Mast erection



April 2, 1957 Filed July 8,

E. A. CAMPBELL MAST ERECTION 3 Sheets-Sheet l INVENTOR.

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E. A. CAMPBELL 2,787,385

MAST ERECTION April 2, 1957 s Shets-Sheet 2 Filed July 8. 1954 IN VEN TOR.

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E. A. CAMPBELL MAST ERECTION April 2, 1957 3 Sheets-Sheet 3 Filed July8. 1954 INVENTOR. few/1V I9 lam eq BY 64 4% m 4! United States Patent Gi MAST ERECTION Erwin A. Campbell, Wexford, Pa, assignor to I .ee C.Moore Corporation, Pittsburgh, Pa., a corporation of PennsylvaniaApplication July 8, 1954, Serial No. 442,031

9 Claims. (Cl. 214-1) This invention relates to the erection of towersor masts, and more particularly to aparatus for swinging them up from areclining position along the ground.

The customary way of erecting skeleton towers or masts, such asstructural steel electric transmission towers is to prepare foundationsupports for the feet of the tower and then construct the tower piece bypiece on the supports. This requires men to work at great heights, withthe accompanying hazards and expense. Of course, in the case oftransmission towers, the electric lines cannot be attached until thetowers have been completely erected. Oil well masts have been erected byswinging them up from reclining positions, but transmission towers whichare erected in permanent locations do not lend themselves to the methodsused in raising oil well masts. Furthermore, oil well derricks includedrawworks which can be used in erecting the masts. No such hoistingequipment is used with electric transmission towers.

It is among the objects of this invention to provide apparatus forerecting electric transmission towers and the like which is independentof the towers, which is carried by a vehicle from one tower to another,which is not removed from the vehicle during use, and which isrelatively simple in construction and operation.

In accordance with this invention, a tower or mast is assembled inreclining position along the ground and has at least two feet. Thesefeet are hinged to supports anchored in the ground, and the recliningmast extends forward away from them. A vehicle, such as a truck ortractor, is drawn up behind the supports and carries a reclining boomwhich extends toward the mast. The inner end of the boom is secured tothe vehicle, preferably pivotally on a horizontal axis. A pulley blockabove the feet is connected with the reclining mast, while sheaves aremounted on the vehicle. Reeved around the sheaves and pulley block is aline, one end of which is attached to a winch on the vehicle. The lineis reeled in by the winch, which swings the mast upward and backward toerect position. On the outer end of the boom there are means bearingagainst the back of the mast hinging means to keep the vehicle apredetermined distance from them while the mast is being raised.Preferably, a gin pole extends upward from the bearing means andsupports a line that connects the pulley block to the mast. This ginpole holds the pulley block at the desired elevation and also keeps theline that fastens the block to the mast from bending any of the crossmembers of the mast.

The invention is illustrated in the accompanying drawings, in which Fig.1 is a plan view of an electric transmission tower about to be raised bymy erecting apparatus;

Fig. 2 is a side view;

Fig. 3 is an enlarged fragmentary plan view of the mast supports;

Fig. 4 is a side view of the same support; h

Figs. 5 and 6 are vertical sections taken on the lines V-V and VI--Vl,respectively, of Fig. 3;

2,787,385 Patented Apr. 2, 1957 Fig. 7 is a fragmentary plan view of oneend of the yoke in retracting position;

Figs. 8 to 11 are schematic views showing the tower in four differentstages of erection; and

Fig. 12 is a fragmentary plan view of a modified embodiment of theinvention.

Referring to Figs. 1 and 2 of the drawings, four concrete foundationpillars 1 project above the ground in positions to support the four feetof a four-legged mast, such as an electric transmission tower 2. Securedto a pair of the concrete pillars, called the front pair forconvenience, are shoes 3 in which the front pair of feet of the towerare pivotally mounted on hinge pins 4. When the tower is reclining, itextends forward along the ground away from the shoes. The rear pair ofshoes 5 are formed for receiving the other pair of feet of the towerafter it has been erected.

Some distance behind the rear foundation blocks is a suitable vehicle 7,a truck being shown for the purpose of illustration. This truck isheaded away from the tower, but is in line with its center. The truckcarries the usual truck winch 8 behind the cab. Mounted on the bed ofthe truck above its rear wheels is a pair of bearing pedestals 9, inwhich a cross shaft 11 is mounted. Pivotally mounted on this shaft isthe inner end of a boom 12 that extends along the ground toward thetower. The boom may be constructed from structural steel elements and ittapers from a wide inner end above the truck to a narrow outer end atthe tower. The outer end of the boom supports a cross beam or yoke 13 bymeans of a vertical pivot pin 14 between them. The front of the oppositeends of the yoke are formed to bear against the back of the hingeconnections between the mast and foundation pillars. Preferably, a fork16 (Fig. 3) projects forward from the front of each end of the yokeastraddle of the shoe 3 in front of it, and the front ends of the forksare provided with recesses that fit around the backs of hinge pins 4. Bybowing the yoke forward so that pivot pin 14 is slightly ahead of thebacksides of the hinge pins, there will be no tendency for the yoke toturn over when pressure is applied to the back of it by the boom.

Also journaled on shaft 11 on the truck is a group of sheaves 18, whichare connected by a line 19 to a pulley block 20 above the lower feet ofthe reclining tower. The pulley block is attached to and supported by abridle cable 21 that extends up over the tower and is connected to itsupper legs several feet from its upper feet. To hold the pulley block ata higher level than otherwise would be the case, and also to prevent thebridle cable from pulling down across the diagonal braces of the towerand possibly bending them, the cable is supported near the block by thetop of a gin pole. The gin pole is formed from a pair of upwardlyconverging legs 22, the lower ends of which are pivotally connected tobrackets 23 on the front of the yoke near its end portions. The upperends of the legs are connected by a saddle member 24, on which thebridle cable rests.

When a tower is ready to be raised, the truck is backedup into theposition shown in Fig. 1, with the opposite ends of yoke 13 behind frontshoes. 3 and with forks 16 engaging hinge pins 4. At this time the ginpole is in a reclining position over the yoke and boom, as indicated inFigs. 7 and 8. To raise the gin pole, a hand line 26 is attached to thecentral part of bridle cable 21 temporarily and threaded through asmatch block 27 hanging from the upper side of the reclining tower. Theline then extends back to the capstan on the truck winch so that thepulley block can be pulled forward. At the same time, a tag line 28between the bridle cable and top of the gin pole is pulled toward thesnatch block, thereby swinging the gin pole upward and forward until itpasses over center. The pole then starts to fall forward by gravity, butit is soon arrested by any suitable means, such as flexible tensionmembers 29 connecting its legs with the yoke. As the gin pole rises, itssaddle 24 engages and lifts the portion of the bridle cable be tween thehand line and pulley block. The hand line is reeled in by the winchuntil the front ends of the bridle cable can be fastened to the upperlegs of the reclining tower. At about the same time theslack tag line 28also is attached to the mast. The hand line and snatch block then areremoved, and the structure appears as shown in Figs. 2 and 9.

The winch then can be operated to reel in line 19 to pull the pulleyblock toward the truck. This will cause the bridle cable to pull againstthe tower and swing it upward and backward. At the beginning otthisoperation the cable will be supported by the gin pole, which will beswung backward with it until the cable lifts free of the pole. The tagline will. prevent the gin pole from falling down onto the boom at thattime, but will lower it slowly with the descending upper feet of thetower, as shown in Fig. 10. When the center of gravity of the towerstarts to pass over shoes 3, a suitable snubbing line (not shown) isused to control the movement of the tower the rest of the way to finalerect position, in which the rear shoes receive the corresponding feetof the tower. The bridle cable and tag line then are disconnected fromthe tower and the truck can be driven away with the boom carrying theyoke behind it.

While the tower is being raised, the boom not only prevents the truckfrom being pulled back toward the mast, but it also prevents therearward pressure of the tower against front shoes 3 from possiblydislodging them from the foundation blocks. That is, while the tower ispushing backward on the shoes, the yoke is pushing forward against themwith the same force, whereby the opposed forces are balanced.

Provision is made for permitting the yoke to pass between the rear legsof the tower when the truck starts away from the tower. This is done byforming the ends of the yoke in such a. way that it can be shortened.This can be accomplished by making the end portions 31 of the yokeseparate from its body and attaching them to forwardly extending arms 32mounted on vertical pivot pins 33 in brackets 34 projecting from thefront of the yoke. While forks 16 are pressed against hinge pins 4, theend portions of the yoke are pressed against its body, but when the yokeis pulled away from the pins the end portions will strike rear shoes 5and be swung around to the positions shown in Fig. 7. reduces the lengthof the yoke sufficiently to permit it to pass between the back shoes.

In the modification shown in Fig. 12, a yoke is not necessary becausethe boom is formed from two beams 35 that diverge toward their outerends. The outer end of each beam is equipped with a form 36 that bearsagainst the hinge pins 37 which fasten the front feet of the tower 38-to the front foundation blocks 39 This form of boom is especiallysuitable for a three-legged tower, because the rear foot 41 can swingdown between the two beams to shoe 42 on block 43.

With the apparatus disclosed herein, transmission towers and the likecan be constructed along the ground and the electric transmission lineseven can be fastened to the arms of a tower before it is raised. Thetower then can be raised to erect position quickly and easily. There isno need to anchor the truck, because the boom will hold it away from thetower. After a tower has been erected, the erecting apparatus can bequickly driven to the next location and put in operating position.

According to the provisions of the patent statutes, I have explained theprinciple of my invention and have illustrated and described what I nowconsider to represent its best embodiment. However, I desire to have itunderstood that; within the scope of the appended 4 claims, theinvention may be practiced otherwise than as specifically illustratedand described.

I claim:

1. Portable erection apparatus for erecting a reclining mast having apair of laterally spaced feet connected by hinging means to fixedsupports, said apparatus comprising a vehicle, a reclining boom securedto the vehicle and extending rearwardly therefrom, a transverse yokemounted on the outer end of the boom and extending laterally away fromits opposite sides, the opposite end-s of the yoke being formed to bearagainst the side of said hinging means opposite to the mast when thevehicle backs the yoke up against them, sheaves mounted on the vehicle,a pulley block behind the sheaves, a line reevcd around the sheaves andpulley block, means secured to the pulley block for detachablyconnecting it to the reclining mast above its feet, and a winch on thevehicle for reeling in the line to swing the mast upward to erectposition.

2. Portable erection apparatus as recited in claim 1, in which the boomis secured to the vehicle on a hozizontal axis.

3. Portable erection apparatus as recited in claim 1, in which said endsof the yoke are pivotally connected to the rest of the yoke on verticalaxes to permit them to be swung away from the vehicle and inward towardeach other after the yoke has been pulled away from said supports.

4. Portable erection apparatus as recited in claim 1, in which thecentral portion of the yoke is bowed away from the vehicle to locate itsconnection to the boom behind the ends of the yoke.

5. Portable erection apparatus as recited in claim 1, in which the boomis pivotally supported on the vehicle on a horizontal axis and ispivotally connected to the yoke on a vertical axis.

6. Portable erection apparatus for erecting a reclining mast having apair of laterally spaced feet connected by hinging means to fixedsupports, said apparatus compris ing a vehicle, a reclining boom securedto the vehicle and extending rearwardly therefrom, a transverse yokemounted on the outer end of the boom and extending laterally away fromits opposite sides, the opposite ends of the yoke being formed to bearagainst the side of said hinging means opposite to the mast when thevehicle backs the yoke up against them, a gin p'ole extending upwardfrom the yoke, sheaves mounted on the vehicle, a pulley block betweenthe sheaves and gin pole, a line reeved around the sheaves and pulleyblock, a cable secured to the pulley block and extending backward overthe top of the gin pole in engagement therewith, the rear end of thecable being adapted to be detachably connected to the reclining mastadjacent the top of the gin pole, and a winch on the vehicle for reelingin the line to swing the mast upward to erect position.

7. Portable erection apparatus as recited in claim 6, in which thebottom of the gin pole is pivotally connected with said yoke so that thetop of the pole can move with said cable.

8. Portable erection apparatus as recited in claim 7, including flexiblemeans secured to the pivoted gin pole and adapted to be detachablyconnected to the mast so that the pole will be lowered by the mast asthe latter is raised.

9'. Portable erection apparatus for erecting a reclining mast having apair of laterally spaced feet mounted on aligned hinge pins on fixedsupports, said apparatus comprising a vehicle, a reclining boom securedto the vehicle and extending rearwardly therefrom, a transverse yokemounted on the outer end of the boom and extending laterally away fromits opposite sides the opposite ends of the yoke being provided withrecessed members for hearing against the side of said hinge pinsopposite to the mast when the vehicle backs the yoke toward the pins,sheaves mounted on the vehicle, a pulley block be- References Cited inthe file of this patent UNITED STATES PATENTS Lunt et a1 Mar. 6, 1934Rogers Feb. 20, 1940

